[单选题]
An electron is known to be confined to a ) -r 28u b lic5rmqe3c,w9bjq (bcz3ccregion of width 0.1 nm. Whmz823 qp ip06uhy t5rvat is an approximate expression0ph5pvq26 i tr 3umyz8 for the least kinetic energy it could have, in eV?
A. $2.7 \; eV$
B. $3.2 \; eV$
C. $3.8 \; eV$
D. $4.3 \; eV$